Generant beads for flexible applications

Abstract

The present invention relates to a new type of gas generant that may be used in airbag inflators. This new type of gas generant is designed to be flexible such that it may be used in side-curtain airbag applications and other situations where flexibility of the gas generant is required or desirable. The gas generant will generally include a flexible igniter, which in some instances, will be an electrical wire. The gas generant also includes one or more beads that are made from a gas-generating material. Each of the beads has a connector passage that is designed such that the flexible igniter may be strung through the connector passage in the beads. In some instances, the connector passage will be a hole in the bead through which the flexible igniter may be passed.

1. A flexible gas generant comprising:
 a flexible igniter; 
 one or more non-cylindrical beads made entirely of a gas-generating material, wherein each bead has a connector passage through which the flexible igniter is strung creating a flexible strand. 
 
     
     
       2. The gas generant as in  claim 1  wherein the flexible igniter is capable of igniting the beads and causing the beads to produce a quantity of gas. 
     
     
       3. The gas generant as in  claim 1  wherein at least one of the beads is a snake-shaped bead. 
     
     
       4. The gas generant as in  claim 1  wherein at least one of the beads is a czech-shaped bead. 
     
     
       5. The gas generant as in  claim 1  wherein the flexible igniter comprises a coating that is selected from the group consisting of PIP-1215, magnalium, and KP. 
     
     
       6. The gas generant as in  claim 1  wherein the flexible igniter comprises a hot wire (typically nichrome) that may or may not be coated with a booster material (such as magnalium and KP), or comprised of metallic fuzed materials. 
     
     
       7. The gas generant as in  claim 1  wherein the heads are constructed free from a flexible binding material. 
     
     
       8. The gas generant as in  claim 1  wherein the beads are strung on the igniter such that each bead restricts rotational movement of each adjacent bead. 
     
     
       9. The gas generant as in  claim 1  wherein the flexible igniter is a wire. 
     
     
       10. The gas generant as in  claim 1  wherein the connector passage is an aperture. 
     
     
       11. The gas generant as in  claim 10  wherein the shape of the shape of the aperture is adjusted in order to tailor the burn rate of the beads. 
     
     
       12. A non-cylindrical gas generant bead comprising:
 a gas-generating material having a shape comprising a connector passage, wherein the non-cylindrical beads are further shaped to engage with and restrict rotational movement of an adjacent bead. 
 
     
     
       13. A gas generant bead as in  claim 12  wherein the shape of the bead is selected from the group consisting of czech-shaped and snake-shaped. 
     
     
       14. A gas generant bead as in  claim 12  wherein the bead is shaped such that a plurality of beads may be strung together by passing a flexible igniter through the connector passage. 
     
     
       15. A gas generant bead as in  claim 12  wherein the bead is free from a flexible binding material. 
     
     
       16. The gas generant as in  claim 1  wherein the flexible strand is capable of being bent at a 90 degree angle.